U.S. patent number 10,124,969 [Application Number 15/610,795] was granted by the patent office on 2018-11-13 for conveyance apparatus, image reading apparatus, and image forming apparatus.
This patent grant is currently assigned to Canon Finetech Nisca Inc.. The grantee listed for this patent is CANON FINETECH NISCA INC.. Invention is credited to Naruhiko Ito, Takatsugu Nakamura, Yuya Tamura, Jianxun Xie, Chiaki Yoshiwara.
United States Patent |
10,124,969 |
Yoshiwara , et al. |
November 13, 2018 |
Conveyance apparatus, image reading apparatus, and image forming
apparatus
Abstract
A conveyance apparatus includes a separation unit configured to
separate and convey a sheet, a detection unit configured to detect
a floating of the sheet passing through the separation unit, and a
control unit configured to stop separate conveyance by the
separation unit if the detection unit detects the sheet for not
less than a predetermined time and/or a predetermined count.
Inventors: |
Yoshiwara; Chiaki (Tsukuba,
JP), Nakamura; Takatsugu (Kawaguchi, JP),
Ito; Naruhiko (Abiko, JP), Tamura; Yuya (Tsukuba,
JP), Xie; Jianxun (Kashiwa, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
CANON FINETECH NISCA INC. |
Saitama |
N/A |
JP |
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Assignee: |
Canon Finetech Nisca Inc.
(Misato-shi, JP)
|
Family
ID: |
60572274 |
Appl.
No.: |
15/610,795 |
Filed: |
June 1, 2017 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170355539 A1 |
Dec 14, 2017 |
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Foreign Application Priority Data
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Jun 8, 2016 [JP] |
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2016-114680 |
Jun 8, 2016 [JP] |
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2016-114683 |
Jun 8, 2016 [JP] |
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2016-114684 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H
3/06 (20130101); H04N 1/00628 (20130101); H04N
1/00689 (20130101); B65H 7/06 (20130101); H04N
1/00713 (20130101); H04N 1/00769 (20130101); H04N
1/00588 (20130101); H04N 1/32646 (20130101); G03G
15/607 (20130101); G03G 15/55 (20130101); H04N
1/00726 (20130101); B65H 7/14 (20130101); H04N
1/00777 (20130101); H04N 1/00801 (20130101); G03G
15/6511 (20130101); B65H 2553/00 (20130101); H04N
2201/0081 (20130101); B65H 2701/1829 (20130101); B65H
7/18 (20130101) |
Current International
Class: |
B65H
5/00 (20060101); B65H 7/14 (20060101); G03G
15/00 (20060101); H04N 1/00 (20060101); B65H
3/06 (20060101); B65H 7/06 (20060101); B65H
7/18 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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05-058512 |
|
Mar 1993 |
|
JP |
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05-085642 |
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Apr 1993 |
|
JP |
|
07-053120 |
|
Feb 1995 |
|
JP |
|
11-37737 |
|
Feb 1999 |
|
JP |
|
2004-107088 |
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Apr 2004 |
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JP |
|
2004-182449 |
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Jul 2004 |
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JP |
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2007-076109 |
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Mar 2007 |
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JP |
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2007-137655 |
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Jun 2007 |
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JP |
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2007-150909 |
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Jun 2007 |
|
JP |
|
2008-169026 |
|
Jul 2008 |
|
JP |
|
2009-292573 |
|
Dec 2009 |
|
JP |
|
2011-195221 |
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Oct 2011 |
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JP |
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2011-195296 |
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Oct 2011 |
|
JP |
|
2011-237251 |
|
Nov 2011 |
|
JP |
|
2013-001573 |
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Jan 2013 |
|
JP |
|
Other References
Jianxun Xie et al., U.S. Appl. No. 15/611,190, filed Jun. 1, 2017.
cited by applicant .
Copending, unpublished U.S. Appl. No. 15/611,190, to Jianxun Xie,
dated Jun. 1, 2017. cited by applicant .
Office Action dated Apr. 16, 2018, in Japanese Patent Application
No. 2017-113617. cited by applicant .
Office Action dated Apr. 23, 2018, in Japanese Patent Application
No. 2017-113616. cited by applicant .
Office Action dated Jul. 20, 2018, in Japanese Patent Application
No. 2017-113613. cited by applicant.
|
Primary Examiner: Sanders; Howard J
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper &
Scinto
Claims
What is claimed is:
1. A conveyance apparatus comprising: a separation unit configured
to separate and convey a sheet; a detection unit configured to
detect a floating of the sheet passing through the separation unit;
a stacking unit configured to stack the sheet to be separated and
conveyed by the separation unit; a pickup roller configured to
convey the sheet stacked on the stacking unit to the separation
unit; and a control unit configured to: perform separate conveyance
by the separation unit if the detection unit does not detect the
floating of the sheet passing through the separation unit; stop
separate conveyance by the separation unit if the detection unit
detects the floating of the sheet for not less than a predetermined
time and/or a predetermined count; and perform separate conveyance
by the separation unit if the detection unit detects the floating
of the sheet for less than the predetermined time and/or the
predetermined count, wherein the detection unit detects the
floating of the sheet on an upstream side of a sheet-conveying
position of the pickup roller with respect to a conveyance
direction of the sheet.
2. The apparatus according to claim 1, wherein the control unit
switches the predetermined time in accordance with a length of the
sheet.
3. The apparatus according to claim 1, wherein the control unit
stops the separate conveyance by the separation unit if a detection
count of the detection unit within the predetermined time is not
less than the predetermined count.
4. The apparatus according to claim 1, further comprising a guide
unit configured to guide the sheet such that the detection unit can
detect the floating of the sheet passing through the separation
unit.
5. The apparatus according to claim 4, wherein the detection unit
comprises a photosensor configured to detect the floating of the
sheet passing through the separation unit, and the guide unit
guides the sheet such that a deformed portion of the sheet crosses
an optical path of the photosensor.
6. The apparatus according to claim 5, wherein the optical path is
set to extend in a widthwise direction orthogonal to the sheet
conveyance direction.
7. The apparatus according to claim 5, wherein the guide unit is
arranged on the upstream side of a detecting position of the
detection unit with respect to the conveyance direction of the
sheet.
8. The apparatus according to claim 4, wherein the guide unit is
arranged at a position close to a lateral side in the widthwise
direction orthogonal to the sheet conveyance direction so as to
abut against a deformed portion of the sheet.
9. The apparatus according to claim 4, further comprising a cover
member configured to cover the separation unit, wherein the guide
unit is provided on the cover member.
10. The apparatus according to claim 9, wherein the guide unit is
provided to project from the cover member to the upstream side with
respect to the conveyance direction of the sheet, and is provided
to reciprocally move in the conveyance direction of the sheet.
11. The apparatus according to claim 10, wherein the cover member
can open/close, and the guide unit retreats to a side of the cover
member coordinately with an opening operation of the cover
member.
12. The apparatus according to claim 1, wherein the detection unit
comprises at least one photosensor configured to detect the
floating of the sheet passing through the separation unit, and the
apparatus further comprises an optical path forming unit configured
to form an optical path such that an optical path of the
photosensor crosses the conveyance path of the sheet.
13. The apparatus according to claim 12, wherein the optical path
forming unit forms the optical path such that the optical path
tilts in the conveyance direction of the sheet with respect to a
widthwise direction of the conveyance path.
14. The apparatus according to claim 12, wherein the optical path
forming unit forms the optical path such that the optical path
tilts in a height direction with respect to a widthwise direction
of the conveyance path.
15. The apparatus according to claim 12, wherein the photosensor
comprises a light-emitting unit and a light-receiving unit, the
light-emitting unit is arranged on one side of the conveyance path
in a widthwise direction, the light-receiving unit is arranged on
the other side of the conveyance path in the widthwise direction,
and the light-emitting unit and the light-receiving unit are
arranged at positions shifted in the conveyance direction of the
sheet.
16. An image reading apparatus comprising: a conveyance apparatus;
and a reading unit configured to read an image of a sheet conveyed
by the conveyance apparatus, wherein the conveyance apparatus
comprises: a separation unit configured to separate and convey the
sheet; a detection unit configured to detect a floating of the
sheet passing through the separation unit; a stacking unit
configured to stack the sheet to be separated and conveyed by the
separation unit; a pickup roller configured to convey the sheet
stacked on the stacking unit to the separation unit; and a control
unit configured to: perform separate conveyance by the separation
unit if the detection unit does not detect the floating of the
sheet passing through the separation unit; stop separate conveyance
by the separation unit if the detection unit detects the floating
of the sheet for not less than a predetermined time and/or a
predetermined count; and perform separate conveyance by the
separation unit if the detection unit detects the floating of the
sheet for less than the predetermined time and/or the predetermined
count, wherein the detection unit detects the floating of the sheet
on an upstream side of a sheet-conveying position of the pickup
roller with respect to a conveyance direction of the sheet.
17. An image forming apparatus comprising: an image reading
apparatus; and an image forming unit configured to form an image
read by the image reading apparatus on a printing medium, wherein
the image reading apparatus comprises: a conveyance apparatus; and
a reading unit configured to read an image of a sheet conveyed by
the conveyance apparatus, and the conveyance apparatus comprises: a
separation unit configured to separate and convey the sheet; a
detection unit configured to detect a floating of the sheet passing
through the separation unit; a stacking unit configured to stack
the sheet to be separated and conveyed by the separation unit; a
pickup roller configured to convey the sheet stacked on the
stacking unit to the separation unit; and a control unit configured
to: perform separate conveyance by the separation unit if the
detection unit does not detect the floating of the sheet passing
through the separation unit; stop separate conveyance by the
separation unit if the detection unit detects the floating of the
sheet for not less than a predetermined time and/or a predetermined
count; and perform separate conveyance by the separation unit if
the detection unit detects the floating of the sheet for less than
the predetermined time and/or the predetermined count, wherein the
detection unit detects the floating of the sheet on an upstream
side of a sheet-conveying position of the pickup roller with
respect to a conveyance direction of the sheet.
18. A conveyance apparatus comprising: a separation unit configured
to separate and convey a sheet; a detection unit comprising at
least one photosensor and configured to detect a floating of the
sheet passing through the separation unit, the photosensor
comprising a light-emitting unit and a light-receiving unit; an
optical path forming unit configured to form an optical path such
that an optical path of the photosensor crosses a conveyance path
of the sheet; and a control unit configured to: perform separate
conveyance by the separation unit if the detection unit does not
detect the floating of the sheet passing through the separation
unit; stop separate conveyance by the separation unit if the
detection unit detects the floating of the sheet for not less than
a predetermined time and/or a predetermined count; and perform
separate conveyance by the separation unit if the detection unit
detects the floating of the sheet for less than the predetermined
time and/or the predetermined count, wherein, the light-emitting
unit is arranged on one side of the conveyance path in a widthwise
direction, the light-receiving unit is arranged on the other side
of the conveyance path in the widthwise direction, and the
light-emitting unit and the light-receiving unit are arranged at
positions shifted in the conveyance direction of the sheet.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a conveyance apparatus, an image
reading apparatus, and an image forming apparatus.
Description of the Related Art
A feeding device included in a copying machine, a scanner, a
facsimile apparatus, or the like is provided with a separation
mechanism configured to separate a plurality of sheets and convey
them one by one to prevent the sheets from being conveyed in an
overlapping state. With such a separation mechanism, documents on a
document stack table can continuously be fed one by one, and images
on the documents can sequentially be read. On the other hand, a
bundle of documents that are bound by a staple or the like so as to
be hard to separate is sometimes erroneously stacked on the
document stack table. If such a bundle of documents passes through
the separation mechanism, the documents may be deformed by the
separating action and damaged. As a measure against this, Japanese
Patent Laid-Open No. 2004-182449 discloses an apparatus provided
with a sensor that detects an abnormal shape state of a document on
the document stack table.
One of the behaviors of a bundle of bound documents passing through
the separation mechanism is the floating of the document on the
upper side. The bundle of bound documents can be detected by
detecting the floating of the document. On the other hand, a
document that is originally folded in a Z shape cannot be flat and
remains wavy even if it is spread out and stacked on the document
stack table. Such a document can be normally read if it is passed
through the separation mechanism and separated and conveyed one by
one, like a normal document. If it is determined whether a document
is a bundle of bound documents or not based on only the floating of
the document, the folded document may erroneously be detected as a
bundle of bound documents.
SUMMARY OF THE INVENTION
According to an aspect of the present invention, there is provided
a conveyance apparatus comprising: a separation unit configured to
separate and convey a sheet; a detection unit configured to detect
a floating of the sheet passing through the separation unit; and a
control unit configured to stop separate conveyance by the
separation unit if the detection unit detects the sheet for not
less than a predetermined time and/or a predetermined count.
Further features of the present invention will become apparent from
the following description of exemplary embodiments (with reference
to the attached drawings).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing the overall arrangement of an image
forming apparatus according to an embodiment of the present
invention;
FIG. 2 is a view showing the overall arrangement of an image
reading apparatus according to an embodiment of the present
invention;
FIG. 3 is an explanatory view of an automatic document feeder;
FIG. 4 is an explanatory view of the automatic document feeder;
FIG. 5 is an explanatory view of deformation detection units;
FIGS. 6A to 6E are views showing examples of document binding by
staples;
FIGS. 7A and 7B are views showing an example of a document
deformation;
FIGS. 8A and 8B are views showing an example of a document
deformation;
FIG. 9 is a block diagram of a control unit;
FIGS. 10A and 10B are explanatory views of a folded document;
FIG. 11A is a view showing the feed form of a folded document;
FIG. 11B is a view showing an example of conditions to discriminate
between a bundle of documents and a folded document;
FIG. 12 is a flowchart showing an example of control;
FIG. 13A is an explanatory view of the detection accuracy of a
detection unit;
FIG. 13B is an explanatory view of a guide member;
FIG. 14 is an explanatory view of a guide member according to
another example;
FIGS. 15A and 15B are explanatory views of the operation of the
guide member according to another example;
FIGS. 16A and 16B are explanatory views of the operation of the
guide member according to another example;
FIGS. 17A and 17B are explanatory views of the operation of the
guide member according to another example; and
FIGS. 18A to 18C are explanatory views of a tilt of an optical
path.
DESCRIPTION OF THE EMBODIMENTS
First Embodiment
FIG. 1 is a view showing the overall arrangement of an image
forming apparatus according to an embodiment of the present
invention. The image forming apparatus includes an image reading
apparatus 1, and a printing unit 300 configured to print an image
read by the image reading apparatus 1 on a sheet (printing medium)
such as paper.
<Printing Unit>
In this embodiment, the printing unit 300 is an image printing unit
using electrostatic latent image formation. Sheets stacked and
stored on an upper cassette 100 are separated and fed one by one by
the action of separation grippers and a feed roller 101 and guided
to a registration roller 106. A lower cassette 102 also includes
separation grippers and a feed roller 103. From a manual feed guide
104, sheets are guided one by one to the registration roller 106
via a roller 105. A deck-type sheet stacking device 108 includes an
inner plate 108a to be vertically moved by a motor or the like.
Sheets on the inner plate 108a are separated and fed one by one by
the action of separation grippers and a feed roller 109 and guided
to a conveyance roller 110.
A developer 114, a transfer charger 115, and a split charger 116
are arranged around a photosensitive drum 112 to form an image
forming unit. A toner image developed on the photosensitive drum
112 is transferred to a sheet conveyed by the registration roller
106. After that, the sheet is conveyed to a fixing device 118 by a
conveying belt 117 to fix the image, and then conveyed to a
diverter 120 by a conveyance roller 119.
To discharge the sheet, the sheet is guided to a discharge roller
121 via the diverter 120 and conveyed into a sorter 122. The sorter
122 includes a non-sort tray 122a, a sort bin tray 122b, a non-sort
tray discharge roller 122c, and a sort bin tray discharge roller
122d. The non-sort tray 122a and the sort bin tray 122b vertically
move to sort the sheets for each stage. Note that a discharge tray
may be attached in place of the sorter.
When performing double-sided copy or multiple copy, a sheet after
fixing is diverted by the diverter 120 and conveyed by a conveyance
roller 201. In double-sided copy, the sheet is discharged to an
intermediate tray 200 via belts 202 and 204, a path 206, and a
discharge roller 205. In multiple copy, the sheet is discharged to
the intermediate tray 200 by a diverter 203. The intermediate tray
200 includes half-moon rollers 209 and 210 configured to feed the
sheet, a separation roller pair 211, and conveyance rollers 213,
214, and 215 configured to convey the sheet to the registration
roller 106.
<Image Reading Apparatus>
The arrangement of the image reading apparatus 1 will be described
with reference to FIG. 2 in addition to FIG. 1. FIG. 2 is a view
showing the overall arrangement of the image reading apparatus 1.
The image reading apparatus 1 includes an automatic document feeder
(to be referred to as a feeding device hereinafter) 2 serving as a
sheet conveyance apparatus, and a reading device 150 that reads a
document fed by the feeder 2. The feeding device 2 is provided to
open/close with respect to the reading device 150.
The reading device 150 includes a reading unit 151, a glass
document table 156, and a platen glass 157. The reading device 150
can select a normal reading mode or a flow reading mode as a
document reading mode. The glass document table 156 forms a light
transmitting unit for the normal reading mode. The platen glass 157
forms a light transmitting unit for the flow reading mode.
The normal reading mode is a mode in which the reading unit 151 is
moved in a sub-scanning direction H under the glass document table
156, thereby scanning a document placed on the glass document table
156 and reading an image on the document. The flow reading mode is
a mode in which the reading unit 151 is kept at rest at a reading
position under the platen glass 157, and an image on a document is
read while conveying the document such that it passes on the platen
glass 157.
The reading unit 151 is, for example, a contact type image sensor,
and includes line sensors arranged in the main scanning direction
orthogonal to the sub-scanning direction H. As the guide structure
of the reading unit 151, the reading device 150 includes a guide
member 152 such as a shaft body extending in the sub-scanning
direction H. The reading unit 151 can reciprocally move in the
sub-scanning direction H along the guide member 152.
The reading device 150 includes a belt transmission mechanism as a
drive mechanism configured to move the reading unit 151. More
specifically, the reading device 150 includes a driving pulley 153
and a driven pulley 154 which are spaced apart in the sub-scanning
direction H. A belt 155 is wound around them. The driving pulley
153 is rotated by a motor 153a. As the driving pulley 153 rotates,
the belt 155 travels. The reading unit 151 is attached to the belt
155. The reading unit 151 moves as the belt 155 travels.
<Feeding Device>
The feeding device 2 will be described with reference to FIGS. 2,
3, and 4. The feeding device 2 conveys a sheet (document) as a
reading target in the flow reading mode. In the following
explanation, an upstream side and a downstream side are defined
based on the sheet conveyance direction.
FIGS. 3 and 4 are explanatory views of the internal arrangement of
the feeding device 2. The feeding device 2 includes a stacking unit
30 on which sheets are stacked. Documents D (sheets D) that are
image reading targets are stacked on a stack surface 30a of the
stacking unit 30.
A pickup roller 31 conveys an uppermost document D of the documents
D stacked on the stacking unit 30 to a separation unit 32. The
feeding device 2 includes a lifting mechanism for the pickup roller
31. At the time of feed, the pickup roller 31 lowers and contacts
the uppermost document D, as shown in FIG. 4. The uppermost
document D is conveyed to the separation unit 32 by the rotation of
the pickup roller 31. At all times other than the time of feed, the
pickup roller 31 is lifted, as shown in FIG. 3. As the lifting
mechanism, a known mechanism can be used.
The separation unit 32 is a unit arranged on the downstream side
with respect to the pickup roller 31 and configured to separate and
convey the documents stacked on the stacking unit 30 one by one. In
this embodiment, the separation unit 32 includes a feed roller 32a
and a retard roller (separation member) 32b that pressure-contacts
the feed roller 32a. The feed roller 32a is rotated to convey the
sheet to the downstream side. The retard roller 32b is provided
with a torque limiter, and is dragged by the feed roller 32a when a
predetermined load acts. If the documents are conveyed to the
separation unit 32 in an overlapping state, the retard roller 32b
is not dragged by the feed roller 32a. The document on the side of
the feed roller 32a is conveyed, and the document on the side of
the retard roller 32b is not conveyed. The documents are thus
separated and conveyed one by one.
Note that as the arrangement of the separation unit 32, an
arrangement that inputs a driving force to the retard roller 32b
via the torque limiter to reverse the retard roller 32b or an
arrangement that uses another separation member such as a
separation pad in place of the retard roller 32b can also be
employed.
The retard roller 32b is rotatably supported by a holder 23. The
holder 23 includes a main body portion 23a and a support portion
23b connected to the main body portion 23a and having the retard
roller 32b mounted on it. A coil spring 24 intervenes between the
main body portion 23a and the support portion 23b. The retard
roller 32b is brought into pressure-contact with the feed roller
32a by the biasing force of the coil spring 24.
The holder 23 is supported to be swingable in the direction of an
arrow d2 about an axis 23c. The feeding device 2 includes a driving
unit 25 capable of separating the feed roller 32a and the retard
roller 32b. The driving unit 25 includes a motor 25a and a cam 25b
that is caused to pivot by the motor 25a. As the cam 25b pivots,
the holder 23 swings about the axis 23c. Unusually, the holder 23
is held at a position where the retard roller 32b pressure-contacts
the feed roller 32a. If a paper jam or the like occurs, the driving
unit 25 makes the holder 23 pivot counterclockwise in FIG. 3 to
separate the retard roller 32b from the feed roller 32a. It is
therefore possible to easily extract the jammed document to the
side of the stacking unit 30.
A conveyance unit 33 is arranged on the downstream side with
respect to the separation unit 32 and conveys a sheet passing
through the separation unit 32. The conveyance unit 33 includes
registration rollers 33a and 33b that are conveyance rollers. They
pressure-contact each other to form a nip portion. One of the
registration rollers 33a and 33b is a driving roller, and the other
is a driven roller. The leading edge of a document is abutted
against the nip portion in a state in which the registration
rollers 33a and 33b are at rest, thereby correcting a skew of the
document.
A platen roller 35 is arranged to face the platen glass 157. A read
roller pair 36 is arranged on the upstream side of the platen
roller 35, and a read roller pair 37 is arranged on the downstream
side. The document passing through the conveyance unit 33 is
conveyed by the read roller pair 36, the platen roller 35, and the
read roller pair 37 so as to pass on the platen glass 157.
A reversing discharge roller pair 38 conveys the document passing
through the read roller pair 37 to a discharge unit 39. The
document is stacked on the discharge unit 39. A flapper 34 that
switches the conveyance path is provided between the read roller
pair 37 and the reversing discharge roller pair 38.
Detection units SR1 to SR7 included in the feeding device 2 will be
described next. The detection unit SR1 is a registration sensor
arranged between the separation unit 32 and the conveyance unit 33
at a point before the conveyance unit 33. The detection unit SR1
includes a flag 11a that freely pivots about an axis 11c, and a
photosensor (photointerrupter) that detects the pivot of the flag
11a. The flag 11a is biased clockwise in FIG. 3 by a spring (not
shown). If the document arrives at the conveyance unit 33, the flag
11a is pushed by the document and pivots, and the arrival of the
document at the conveyance unit 33 can be detected. Then, the
conveyance unit 33 is controlled based on the detection result of
the detection unit SR1 to correct the skew of the document. More
specifically, the rotation of the conveyance unit 33 is stopped
until a predetermined time elapses from document detection by the
detection unit SR1. After the elapse of the predetermined time,
control is done to rotate the conveyance unit 33 to do conveyance,
thereby correcting the skew of the document.
The detection units SR2 and SR3 are sensors having the same
arrangement as the detection unit SR1. The detection unit SR2 is a
read sensor that detects that the leading edge of the document
passes through the read roller pair 36. The start/end of reading of
the reading unit 151 is controlled based on the detection result of
the detection unit SR2. The detection unit SR3 is a discharge
sensor that detects that the leading edge of the document reaches a
point before the flapper 34.
The detection unit SR4 is a sensor that detects multi feed of
documents, and is sometimes called a multi feed detection sensor.
The detection unit SR4 detects multi feed of documents on the
downstream side of a sheet-conveying position of the separation
unit 32 and on the upstream side of a sheet-conveying position of
the conveyance unit 33. In this embodiment, the detection unit SR4
is an ultrasonic sensor. A transmitter 14a and a receiver 14b are
arranged on both sides of a conveyance path RT1. If multi feed is
detected by the detection unit SR4, conveyance of the document D is
stopped.
Each of the detection units SR5 and SR6 is a sensor that detects a
deformation of the sheet, and is sometimes called a deformation
detection sensor. Details will be described later. The detection
unit SR7 is a post-separation sensor that is arranged immediately
after the nip portion of the separation unit 32 and detects that
the leading edge of the document passes through the separation unit
32. The detection unit SR7 can be, for example, a sensor having the
same arrangement as the detection unit SR1.
The detection unit SR8 is a document detection sensor that detects
whether the document D is stacked on the stacking unit 30. In this
embodiment, its detection position is set on the downstream side of
a sheet-conveying-conveying position of the pickup roller 31 and on
the upstream side of the sheet-conveying-conveying position of the
separation unit 32. The detection unit SR8 can be, for example, a
sensor having the same arrangement as the detection unit SR1.
Each of the detection units SR9 and SR10 is a document length
sensor that detects the length of the document D. In this
embodiment, their detection positions are set apart in the
conveyance direction in the stacking unit 30. The detection units
SR9 and SR10 are, for example, reflection photosensors. As for the
document length, for example, if both the detection units SR9 and
SR10 detect the document D, the size can be determined to be large.
If only the detection unit SR9 detects the document D, the size can
be determined to be small.
The feeding device 2 includes a main body unit 20 and a cover
member 21. The cover member 21 covers the above-described
components such as the pickup roller 31, the separation unit 32,
and the conveyance unit 33 from above. The cover member 21 is
connected to the main body unit 20 via a hinge portion 22 and
freely pivots in the direction of an arrow d1 about the hinge
portion 22 serving as the pivot center. Accordingly, as the cover
member 21 pivots, the feeding device 2 can be opened/closed, and
maintenance can be done if a paper jam or the like occurs. In
addition, the pickup roller 31, the feed roller 32a, and the like
are supported by the cover member 21. When the cover member 21 is
opened, these components move together with the cover member 21. As
a result, the maintainability further improves.
An example of the operation of the feeding device 2 in the flow
reading mode will be described next. If the detection unit SR8
detects the document D placed on the stacking unit 30 by the user,
the document D is pulled into the apparatus by the pickup roller 31
and conveyed to the separation unit 32. Even if a plurality of
documents are conveyed in a multi feed state, the separation unit
32 separates the documents and conveys them one by one to the
conveyance unit 33.
If the detection unit SR1 detects the leading edge of the document
D, the leading edge of the document D conveyed by the separation
unit 32 is abutted against the conveyance unit 33 that has stopped
rotating, thereby correcting a skew of the document D. The
detection unit SR1 can be used not only to measure the timing of
correcting the skew of the document D but also to measure the feed
timing for the next document by the pickup roller 31 in accordance
with detection of the trailing edge of the document D.
The document D that has undergone the skew correction is conveyed
to the read roller pair 36. Image reading by the reading unit 151
is started at a reading timing based on detection of the leading
edge of the document D by the detection unit SR2. At this time, the
reading unit 151 reads the image of the document D that is conveyed
in a state in which the floating amount from the upper surface of
the platen glass 157 is regulated by the platen roller 35 that
rotates at a predetermined rotational speed.
The document D is conveyed by the read roller pairs 36 and 37 while
its image is read by the reading unit 151. When reading only one
surface of the document D, the document D that has undergone the
image reading is conveyed by the read roller pair 37 to the
reversing discharge roller pair 38 and discharged to the discharge
unit 39.
When reading both surfaces of the document D, after the reading of
the first surface, the reversing discharge roller pair 38 that is
discharging the document D is stopped. After that, the reversing
discharge roller pair 38 is rotated in the reverse direction to
bring the document D back into the apparatus. Then, the flapper 34
switches the conveyance path to a reversing conveyance path RT2 to
feed the document D to the conveyance path RT1 again. The reading
unit 151 reads the second surface in accordance with the same
procedure as described above. After that, the document is
discharged to the discharge unit 39, as in the single-sided
reading.
<Detection of Sheet Deformation>
In this embodiment, the detection units SR5 and SR6 are arranged to
detect a deformation, in particular, floating of the document which
occurs when a bundle of documents bound by a staple or the like
passes through the separation unit 32. The floating of the sheet
means a deformation of the sheet in a height direction at a side of
the feed roller 32a of the separation unit 32. The detection units
SR5 and SR6 are arranged so as to detect a sheet at a level higher
than a level where a conveyed sheet passes in a normal state, and
therefore the detection units SR5 and SR6 detect a sheet conveyed
by the separation unit 32 in an abnormal state. FIG. 5 is an
explanatory view of the detection units SR5 and SR6. Referring to
FIG. 5, an arrow X represents the conveyance direction of the
document (the path direction of the conveyance path RT1), and an
arrow Y represents the widthwise direction of the conveyance path
RT1.
The detection unit SR5 is a sensor that detects the deformation of
the sheet passing through the separation unit 32 at a position on
the downstream side of the sheet-conveying position of the
separation unit 32 and on the upstream side of the sheet-conveying
position of the conveyance unit 33. Thus, the detecting position of
the detection sensor SR5 is set at a position on the downstream
side of the sheet-conveying position of the separation unit 32 and
on the upstream side of the sheet-conveying position of the
conveyance unit 33. In this embodiment, the detection unit SR5
detects the deformation of the sheet at a position closer to the
separation unit 32 than the conveyance unit 33. This enables
quicker detection of the sheet deformation that occurs on the
downstream side of the sheet-conveying position of the separation
unit 32.
The detection unit SR6 is a sensor that detects the deformation of
the sheet passing through the sheet-conveying position of the
separation unit 32 at a position on the upstream side of the
sheet-conveying position of the separation unit 32. Thus, the
detecting position of the detection unit SR6 is set at a position
on the downstream side of the sheet-conveying position of the
separation unit 32. In this embodiment, the detection unit SR6 is
arranged to detect the deformation of the sheet at a position on
the upstream side of the sheet-conveying position of the pickup
roller 31. It is therefore possible to more quickly detect the
sheet deformation that occurs on the upstream side of the
sheet-conveying position of the separation unit 32.
In this embodiment, the detection units SR5 and SR6 are
transmission-type photosensors. However, these sensors may be
sensors of another type. For example, they may be flag-type sensors
like the detection unit SR1.
The detection unit SR5 includes a light-emitting portion 15a and a
light-receiving portion 15b. The light-emitting portion 15a and the
light-receiving portion 15b are arranged on one lateral side and
the other lateral side of the conveyance path RT1 in the widthwise
direction Y, and face each other. The light-emitting portion 15a
and the light-receiving portion 15b are arranged at an interval
larger than the width of a document in the maximum size. An optical
path L5 from the light-emitting portion 15a to the light-receiving
portion 15b is set to cross the conveyance path RT1. In this
embodiment, the optical path L5 is parallel to the widthwise
direction Y. However, the optical path L5 may tilt with respect to
the widthwise direction Y.
The optical path L5 is set at a position apart upward from the
conveyance plane of the conveyance path RT1. This can prevent a
document that is normally conveyed from being erroneously
detected.
In this embodiment, the detection unit SR6 is formed like the
detection unit SR5. The detection unit SR6 includes a
light-emitting portion 16a and a light-receiving portion 16b. The
light-emitting portion 16a and the light-receiving portion 16b are
arranged on one lateral side and the other lateral side of the
stacking unit 30 in the widthwise direction Y, and face each other.
The light-emitting portion 16a and the light-receiving portion 16b
are arranged at an interval larger than the width of a document in
the maximum size. An optical path L6 from the light-emitting
portion 16a to the light-receiving portion 16b is set to cross the
stack surface 30a of the stacking unit 30. In this embodiment, the
optical path L6 is parallel to the widthwise direction Y. However,
the optical path L6 may tilt with respect to the widthwise
direction Y.
The optical path L6 is set at a position apart upward from the
stack surface 30a and set at a position higher than the upper limit
height of stacked documents. This can prevent a document that is
normally conveyed from being erroneously detected.
Examples of document deformation detectable by the detection units
SR5 and SR6 will be described next. Types of a bundle of documents
bound by staples and examples of deformation will be described
first with reference to FIGS. 6A to 6E and FIGS. 7A to 8B. In FIGS.
6A to 6E, arrows indicate the document conveyance direction.
FIG. 6A shows a bundle of documents bound by a plurality of staples
ST along the edge on the trailing edge side in the conveyance
direction. FIG. 7A shows the behavior of the bundle of documents
passing through the separation unit 32. In the bundle of documents
bound on the trailing edge side, the conveyance of the document D
(uppermost document) on the side of the feed roller 32a progresses,
and the conveyance of the document D on the side of the retard
roller 32b stops due to the separation action of the separation
unit 32 on the leading edge side. For this reason, the trailing
edge side of the bundle of documents bound by the staples ST floats
in a loop shape. In this example, since the bundle of documents is
bound by the plurality of staples ST along the edge, the trailing
edge side of the bundle of documents floats in a wavy pattern
almost evenly in the widthwise direction. Such a deformation can be
detected by the detection unit SR6.
FIG. 6B shows a bundle of documents bound by the staple ST at one
corner on the trailing edge side in the conveyance direction. FIG.
7B shows the behavior of the bundle of documents passing through
the separation unit 32. In the bundle of documents bound on the
trailing edge side, the conveyance of the document D (uppermost
document) on the side of the feed roller 32a progresses, and the
conveyance of the document D on the side of the retard roller 32b
stops due to the separation action of the separation unit 32 on the
leading edge side. For this reason, the trailing edge side of the
bundle of documents bound by the staple ST floats in a loop shape.
In this example, since the bundle of documents is bound by the
staple ST at one corner, the trailing edge side of the bundle of
documents floats unevenly in the widthwise direction, and the side
of the staple ST floats higher. Such a deformation can be detected
by the detection unit SR6.
FIG. 6C shows a bundle of documents bound by the plurality of
staples ST along the edge on the leading edge side in the
conveyance direction. FIG. 8A shows the behavior of the bundle of
documents passing through the separation unit 32. For the bundle of
documents bound on the leading edge side, the separation action of
the separation unit 32 tends to be effective after the staples ST
pass through the separation unit 32. Additionally, on the trailing
edge side of the bundle of documents, the documents are not
restrained. For this reason, the leading edge side of the bundle of
documents bound by the staples ST floats in a loop shape on the
downstream side of the sheet-conveying position of the separation
unit 32. In this example, since the bundle of documents is bound by
the plurality of staples ST along the edge, the leading edge side
of the bundle of documents floats in a wavy pattern almost evenly
in the widthwise direction. Such a deformation cannot be detected
by the detection unit SR6. In this embodiment, however, the
detection unit SR5 or SR4 can detect the deformation.
FIG. 6D shows a bundle of documents bound by the staple ST at one
corner on the leading edge side in the conveyance direction. FIG.
8B shows the behavior of the bundle of documents passing through
the separation unit 32. As in the example shown in FIGS. 6C and 8A,
the leading edge side of the bundle of documents bound by the
staple ST floats in a loop shape on the downstream side of the
sheet-conveying position of the separation unit 32. In this
example, since the bundle of documents is bound by the staple ST at
one corner, the leading edge side of the bundle of documents floats
unevenly in the widthwise direction, and the side of the staple ST
floats higher. Such a deformation cannot be detected by the
detection unit SR6. The detection unit SR4 can detect the
deformation in some cases. However, depending on the deformation
pattern, the document D does not overlap at the detection position
of the detection unit SR4, and the deformation may be undetectable.
In this embodiment, however, the detection unit SR5 can detect the
deformation.
FIG. 6E shows a bundle of documents bound by the staples ST on a
lateral side in the conveyance direction. The behavior of the
bundle of documents passing through the separation unit 32 is the
same as in the example of FIG. 8B. The detection unit SR5 can
detect the deformation.
As described above, in this embodiment, since the detection unit
SR5 is provided, the bundle of documents bound on the leading edge
side in the conveyance direction can be detected more quickly.
<Determination of Bundle of Bound Documents and Folded
Document>
A document folded in a Z shape cannot be flat and remains wavy even
if it is spread out and stacked on the stacking unit 30. FIGS. 10A
and 10B show an example of such a folded document. FIG. 10A shows a
document folded in a Z shape, and FIG. 10B shows a state in which
the document shown in FIG. 10A is spread out. Even in the spread
state as shown in FIG. 10B, a mountain-shaped crease remains.
Such a folded document normally passes through the separation unit
32 without any problem. However, if the folded document is fed, the
mountain portion passes on the optical path L6 of the detection
sensor SR6, as shown in FIG. 11A, and is detected by the detection
sensor SR6. Hence, if it is determined that the document is a
folded document only based on the detection of the floating of the
document by the detection sensor SR6, a detection error can
occur.
To prevent this, a bundle of bound documents and a folded document
are discriminated based on their behaviors. FIG. 11B is a view
showing an example of conditions to discriminate between a bundle
of bound documents and a folded document. The continuous time
(continuous ON time T) of detection by the detection sensor SR6
changes between the bundle of bound documents and the folded
document. More specifically, in the bundle of bound documents, the
document on the upper side floats, as shown in FIGS. 7A and 7B.
Additionally, by the action of the separation unit 32, the floating
state is maintained on the upstream side of the sheet-conveying
position of the separation unit 32. Hence, the detection time of
the detection sensor SR6 becomes relatively long. On the other
hand, in the folded document, conveyance of the document is not
impeded by the separation unit 32. Since the mountain portion
passes through the optical path L6 in accordance with feeding, the
detection time of the detection sensor SR6 becomes relatively
short. It is therefore possible to make a discrimination between
the bundle of bound documents and the folded document based on the
continuous ON time T of the detection unit SR6.
The continuous ON time T serving as a threshold to discriminate
between the bundle of bound documents and the folded document can
be changed depending on the document conveyance speed, the document
length, or the document type (thickness or the like). In the
example shown in FIG. 11B, the time serving as the threshold to
discriminate between the bundle of documents and the folded
document is changed depending on the document length. For a small
size, if the continuous ON time T of the detection unit SR6 is 100
ms or more, the document is determined to be a bundle of bound
documents. If the continuous ON time T is less than 100 ms, the
document is determined to be a folded document. For a large size,
if the continuous ON time T of the detection unit SR6 is 200 ms or
more, the document is determined to be a bundle of bound documents.
If the continuous ON time T is less than 200 ms, the document is
determined to be a folded document. The size of the document
stacked on the stacking unit 30 can be determined based on the
detection results of the detection units SR9 and SR10, as described
above.
In addition, the detection count (intermittent ON count N) of the
detection sensor SR6 per unit time changes between the bundle of
bound documents and the folded document. More specifically, in the
bundle of bound documents, the document on the upper side floats,
as shown in FIGS. 7A and 7B. Additionally, by the action of the
separation unit 32, the floating state is maintained on the
upstream side of the sheet-conveying position of the separation
unit 32. At this time, the floating portion vibrates in a swinging
manner due to the separation operation of the separation unit 32
for the bundle of documents. For this reason, the floating portion
tends to cross the optical path L6 a plurality of times, and the
count of repetitive ON-OFF of the detection sensor SR6 becomes
relatively large. On the other hand, in the folded document, since
the separation unit 32 performs a normal separation operation, the
vibration factor is small. Since the climbing and descending
portions of the mountain pass through the optical path L6, the
detection count is 2. For this reason, if the detection count of
the detection sensor SR6 is 2 or less, the document can be
determined to be a folded document. If the detection count is 3 or
more, the document can be determined to be a bundle of bound
documents. It is therefore possible to make a discrimination
between the bundle of bound documents and the folded document based
on the intermittent ON count N of the detection unit SR6.
The intermittent ON count N serving as a threshold to discriminate
between the bundle of bound documents and the folded document can
be changed depending on the document conveyance speed, the document
length, or the document type (thickness or the like). In the
example shown in FIG. 11B, the count serving as the threshold to
discriminate between the bundle of documents and the folded
document is changed depending on the document length. For a folded
document whose document length is long (document size is large),
the detection count may be large because of a swing or floating on
the upstream side of the mountain portion. Even so, the detection
count is probably about 4. Hence, for a large document size, if the
detection count N of the detection sensor SR6 is 2 to 4 or less,
the document is determined to be a folded document. If the
detection count N is 5 or more, the document can be determined to
be a bundle of bound documents.
When a bundle of documents and a folded document are discriminated
in this way, it is possible to accurately detect a bundle of bound
documents and execute corresponding control (for example, feeding
stop). Note that such a discrimination between a bundle of
documents and a folded document can also be applied to the
detection result of the detection sensor SR5.
<Control>
A control system provided in the feeding device 2 will be described
with reference to FIG. 9. The control circuit of the feeding device
2 is formed with a control unit 40 as the main component. The
control unit 40 is, for example, a microcomputer including a CPU, a
memory for storing data and programs to be executed by the CPU, and
an interface to an external device. The detection units SR1 to SR10
are connected to the input ports of the control unit 40. A motor
44, a pick lowering solenoid 41, a feed clutch 42, and a
registration clutch 43 are connected to the output ports. The motor
44 includes various kinds of motors. The various kinds of motors
include, for example, motors serving as the driving sources of the
pickup roller 31, the feed roller 32a, and the registration roller
33a or 33b and the motor 25a. In this embodiment, an arrangement in
which the pickup roller 31, the feed roller 32a, and the
registration roller 33a or 33b are driven by a common conveyance
motor is assumed.
The pick lowering solenoid 41 is a solenoid configured to lower the
pickup roller 31. The pickup roller 31 is biased to the rising
position by a spring (not shown). When the pick lowering solenoid
41 is driven, the pickup roller 31 lowers to the lowering position
and abuts against the document D stacked on the stacking unit 30.
The feed clutch 42 is an electromagnetic clutch that interrupts the
driving force of the conveyance motor to the feed roller 32a and
the pickup roller 31. The registration clutch 43 is an
electromagnetic clutch that interrupts the driving force of the
conveyance motor to the registration roller 33a or 33b.
An example of feed control executed by the control unit 40 will be
described with reference to FIG. 12. Control to make a
discrimination between a bundle of documents and a folded document
based on the detection result of the detection unit SR6 and switch
processing in a case in which the document D is fed from the
stacking unit 30 to the downstream side of the conveyance unit 33
will be exemplified here.
When the user sets the document D on the stacking unit 30, and the
document detection sensor SR8 detects the document (step S100), in
step S101, the document length is detected based on the detection
results of the document length detection sensors SR9 and SR10. The
size is determined as small if only the detection unit SR9 is ON or
as large if both the detection units SR9 and SR10 are ON, as
described above. In step S102, feeding is started. More
specifically, the pick lowering solenoid 41 is driven to lower the
pickup roller 31 and abut it against the uppermost document D
stacked on the stacking unit 30. In addition, the feed clutch 42 is
connected to transmit the driving force of the conveyance motor to
the pickup roller 31 and the feed roller 32a, and feeding is
started.
If the deformation detection sensor SR6 detects a floating of the
document D during conveyance of the document D, the process
advances to step S104. If a floating is not detected, the process
advances to step S114 to perform a reading operation. In steps S104
to S106, the conditions to discriminate between a bundle of
documents and a folded document are set based on the detection
result of step S101. Here, a discrimination is made depending on
whether the document length is 210 mm or more (whether the size is
small or large). If the size is large (not less than 210 mm), the
process advances to step S105 to set the continuous ON time T
serving as a threshold to 200 msec and set the intermittent ON
count N to 5. If the size is small (less than 210 mm), the process
advances to step S106 to set the continuous ON time T serving as a
threshold to 100 msec and set the intermittent ON count N to 3. At
this time, as for the document size determination, if both the
detection units SR9 and SR10 are ON in step S101, it is determined
that the document length is 210 mm or more, and the size is large.
If only the detection unit SR9 is ON, it is determined that the
document length is less than 210 mm, and the size is small. In step
S107, measurement of the continuous ON time T and the intermittent
ON count N of the deformation detection sensor SR6 is started.
In step S108, it is determined whether the continuous ON time T is
equal to or more than the threshold set in step S105 or S106. If
the continuous ON time T of the deformation detection sensor SR6 is
equal to or more than the threshold, the document is determined to
be a bundle of bound documents, and the process advances to step
S110. If the continuous ON time T of the deformation detection
sensor SR6 is less than the threshold, the process advances to step
S109. In step S109, it is determined whether the intermittent ON
count N within a predetermined time is equal to or more than the
threshold set in step S105 or S106. If the intermittent ON count N
of the deformation detection sensor SR6 is equal to or more than
the threshold, the document is determined to be a bundle of bound
documents, and the process advances to step S110. If the
intermittent ON count N of the deformation detection sensor SR6 is
less than the threshold, the document is determined to be a folded
document, and the process advances to step S114.
In this embodiment, the discrimination between the bundle of
documents and the folded document is made based on two conditions,
that is, the continuous ON time T and the intermittent ON count N
of the deformation detection sensor SR6. However, the
discrimination may be done based on only the continuous ON time T.
However, if the discrimination is done based on the two conditions,
the detection accuracy can further be improved.
In step S110, control to stop the job is performed. In this
control, for example, the feed clutch 42 is disconnected to cut off
the transmission of the driving force of the conveyance motor to
the feed roller 32a. The conveyance of the document D by the
separation unit 32 thus stops.
In step S111, it is determined whether the user inputs a retry
request. If a retry request is input, the process advances to step
S112 to reduce the conveyance speed of the document D. Then, the
process returns to step S102 to perform feeding again. If a retry
request is not input, the process advances to step S113 to perform
processing associated with a staple error, and the processing ends.
In step S113, for example, the retard roller 32b may be separated
from the feed roller 32a by the driving unit 25. In addition, the
user is notified of the occurrence of the error. The notification
can be made by a voice or display by a display device.
In step S114, the reading operation is executed. After that, the
process returns to step S100. If the document detection sensor SR8
detects the next document, the same processing as described above
is performed. If the next document is not detected, the processing
ends.
As described above, even with the arrangement for detecting the
floating of a document, it is possible to suppress an error of
detecting a folded document as a bundle of documents bound by a
staple or the like and accurately detect the bundle of bound
documents.
In addition, since such a detection error can be prevented, reading
can be done by a normal flow reading operation without stopping
conveyance of a folded document. It is therefore possible to
prevent conveyance of a folded document capable of normally being
read from stopping and prevent the user from being promoted to set
the document again.
Although conveying the documents D by the separation unit 32 is
stopped based on the detection result of the detection unit SR6 in
the first embodiment, conveying sheets can be stopped in the whole
apparatus 1 when the bundle of bound documents is detected. In this
case, each conveying section in the apparatus 1 can simultaneously
be stopped, or each conveying section in the apparatus 1 can be
stopped in order from a conveying section which is conveying a
sheet. In a case that there is a sheet which is normally conveyed
at the downstream side of the sheet-conveying position of the
separation unit 32 when the conveying documents D by the separation
unit 32 should be stopped, each conveying section in the apparatus
1 can be stopped after discharging the sheet.
Second Embodiment
A guide member configured to guide a deformation of a sheet passing
through a separation unit 32 may be provided. FIGS. 13A and 13B
show an example of a guide member 50. The guide member 50 is
provided on a cover member 21.
<Guide Member>
The guide member 50 will be described. The guide member 50 is
provided to guide a deformed portion of a sheet passing through the
separation unit 32 into an orientation corresponding to detection
by a detection unit SR6. In this embodiment, since the detection
unit SR6 is a photosensor, the deformed portion of the sheet is
guided such that it crosses an optical path L6. This will be
described in detail with reference to FIGS. 13A and 13B.
If the trailing edge in the conveyance direction is bound by a
plurality of staples ST along the edge, as shown in FIG. 6A, the
end of the bundle of documents floats in a wavy pattern almost
evenly in the widthwise direction, as shown in FIG. 7A, and the
planar direction of a floating document D becomes almost parallel
to a widthwise direction Y. In a case in which the optical path L6
is almost parallel to the widthwise direction Y, if the document D
is thin, the document D may be unable to sufficiently interfere
with light on the optical path L6, the detection unit SR6 may be
unable to detect the floating of the document D, and the bundle of
documents may be passed. FIG. 13A schematically shows a case in
which the optical path L6 is parallel to the widthwise direction Y.
As shown in FIG. 13A, if the optical path L6 is almost parallel to
the widthwise direction Y, the planar direction of the document D
and the optical path L6 are almost parallel, and the light on the
optical path L6 may not be shielded by the document D.
The guide member 50 obliquely tilts the portion that floats in a
loop shape to make the planar direction of the document D cross the
optical path L6 so that the document D can easily shield the light
on the optical path. This can improve the accuracy of detecting the
deformation of the document D. When the accuracy of detecting the
deformation of the document D improves, conveyance of the bundle of
bound documents can correctly be stopped. It is therefore possible
to prevent damage to the bundle of documents.
FIG. 13B shows the guide form of the deformed portion of the
document D by the guide member 50. In this embodiment, the guide
member 50 is a plate-shaped member projecting from the end of the
cover member 21 to the upstream side (the side of a stacking unit
30) in the sheet-conveyance direction. The guide member 50 is
located at a position closer to a lateral side than the center of a
conveyance path RT1 (or to a lateral side than the center of a
stack surface 30a), and abuts against an end of a bundle of
documents deformed into a loop shape and traveling in the
conveyance direction. When the end of the bundle of documents,
which floats in a wavy pattern almost evenly in the widthwise
direction, abuts against the guide member 50, traveling is
relatively delayed on the abutting side but relatively progresses
on the non-abutting side. As a result, the floating portion tilts
with respect to the widthwise direction. The position of the guide
member 50 can be set such that, for example, it abuts against a
region corresponding to 1/4 of the width of the document D from one
side edge of the document D in the widthwise direction.
As a result, the planar direction of the document D crosses the
optical path L6, the light on the optical path is shielded by the
document D, and the floating of the document D is detected by the
detection sensor SR6.
Although the guide member 50 promotes to detect the floating of the
document D by the detection sensor SR6, a folded document may be
erroneously detected as a bundle of bound documents. However, a
bundle of bound documents can be precisely detected by
discriminating between a bundle of documents and a folded document
based on the detection time or the detection count as the first
embodiment. Further, since such an erroneous detection can be
prevented, the flow reading mode can be conducted without stopping
conveying a folded document. It is therefore possible to prevent
conveyance of a folded document capable of normally being read from
stopping and prevent the user from being promoted to set the
document again.
The guide member 50 may be provided independently of the cover
member 21. However, when the guide member 50 is provided using the
cover member 21, the number of parts can be reduced. When the guide
member 50 is formed integrally with the cover member 21, the number
of parts can further be reduced.
The guide member 50 can have any shape as long as the deformed
portion of the document D can be guided in the above-described way,
and the arrangement point can also appropriately be changed. In
this embodiment, the guide member 50 is provided for the detection
sensor SR6. However, a guide member having the same function as the
guide member 50 may be provided for another detection sensor.
In addition, the guide member 50 can be applied to a sensor other
than a transmission-type photosensor like the detection unit SR6.
In this case as well, it need only guide the deformed portion of
the sheet to improve the detection accuracy of the sensor.
Modification of Second Embodiment
In the control according to the first embodiment, if a bundle of
documents bound on the trailing edge is detected by the detection
unit SR6, the separation unit 32 is stopped to stop feeding of the
bundle of documents. The user can open the cover member 21 and
extract the bundle of documents. However, the guide member 50
projects from the end of the cover member 21 and may therefore be
an obstacle when the user extracts the bundle of documents. For
example, the loop portion of the bundle of documents may be caught
on the guide member 50. If the cover member 21 is forcibly opened
in this state, the bundle of documents may be damaged.
FIG. 14 shows an example of the arrangement of a guide member 60
according to a modification. The guide member 60 has, at one end,
an abutting portion 60a that abuts against the document D. The
abutting portion 60a forms a movable member that can reciprocally
move in the conveyance direction of the sheet. The guide member 60
is movable. For this reason, when the user opens the cover member
21 and extracts the bundle of documents, the abutting portion 60a
is retreated to the side of the cover member 21, thereby avoiding a
situation in which the guide member 60 becomes an obstacle when
opening the cover member 21.
In the modification, the guide member 60 is configured to move
coordinately with the opening operation and the closing operation
of the cover member 21. Hence, the user can displace the guide
member 60 without separately operating the cover member 21 and the
guide member 60. The structure will be described below with
reference to FIGS. 15A to 17B in addition to FIG. 14. FIGS. 15A to
16A are operation explanatory views showing the operation of the
guide member 60 obliquely from above through the cover member 21.
FIG. 15A shows a case in which the cover member 21 is closed. FIG.
15B shows a state in which the cover member 21 starts opening. FIG.
16A shows a state in which the cover member 21 is slightly opened.
FIGS. 16B to 17B are operation explanatory views showing the
operation of the guide member 60 from the outside of the feeding
device 2. FIGS. 16B to 17B correspond to the states of the cover
member 21 shown in FIGS. 15A to 16A, respectively.
The guide member 60 is pivotally supported by the cover member 21
at an axial portion 61a. The guide member 60 may be configured to
translate in the conveyance direction. However, when the guide
member 60 is configured to pivot, the abutting portion 60a can be
moved more largely by a smaller moving amount (pivot amount) of the
guide member 60. A projecting portion 62 projecting downward is
formed at the other end of the guide member 60. The projecting
portion 61b is provided to abut against a leaf spring 62 supported
by a frame 63 of the main body 20.
The leaf spring 62 tilts obliquely downward in the conveyance
direction of the sheet, and applies a biasing force in the
conveyance direction to the projecting portion 61b abutting against
the leaf spring 62. By this biasing force, the guide member 60 is
given a pivotal habit in a direction in which the abutting portion
60a projects from an end of the cover member 21.
On the other hand, a coil spring 64 is provided between the guide
member 60 and the cover member 21. By the biasing force of the coil
spring 64, the guide member 60 is given a pivotal habit in a
direction in which the abutting portion 60a retreats from the end
of the cover member 21 into the apparatus.
The behavior of the guide member 60 coordinated with the opening
operation of opening the cover member 21 from a closed state will
sequentially be explained. FIGS. 15A and 16B show a case in which
the cover member 21 is in a closed state. In this state, the
projecting portion 61b abuts against the leaf spring 62. The
biasing force of the leaf spring 62 is set to be larger than that
of the coil spring 64, and the abutting portion 60a projects from
the end of the cover member 21. In this state, the abutting portion
60a functions like the guide member 50 according to the first
embodiment, and guides the deformed portion of the sheet into an
orientation corresponding to detection by a detection unit SR6.
FIGS. 15B and 17A show a case in which the cover member 21 starts
opening. If the cover member 21 starts opening, the guide member 60
starts separating upward from the main body 20. For this reason,
the projecting portion 61b starts separating from the leaf spring
62, the biasing force of the leaf spring 62 stops acting on the
projecting portion 61b, and the biasing force of the coil spring 64
becomes larger. For this reason, the guide member 60 starts
pivoting as shown in FIG. 13B, and the abutting portion 60a starts
retreating from the end of the cover member 21 to the downstream
side.
FIGS. 16A and 17B show a state in which the cover member 21 is
slightly opened, that is, a state in which the opening of the cover
member 21 has progressed as compared to the state shown in FIGS.
15B and 17A. The projecting portion 61b is completely separated
from the leaf spring 62, and the pivotal movement of the guide
member 60 further progresses by the biasing force of the coil
spring 64. The abutting portion 60a retreats from the end of the
cover member 21 into the apparatus.
In this way, the guide member 60 pivots coordinately with the
opening operation of the cover member 21, and the abutting portion
60a retreats. For this reason, even if the bundle of documents is
caught on the abutting portion 60a, the catch is eliminated
automatically by opening the cover member 21. If the cover member
21 is returned to the closed state after removal of the bundle of
documents, the projecting portion 61b abuts against the leaf spring
62 again. By the biasing force, the guide member 60 returns to the
state shown in FIGS. 15A and 16B, and thus returns to the state in
which the abutting portion 60a projects from the cover member 21.
Note that the above-described moving mechanism of the guide member
60 is merely an example, and another mechanism that exhibits the
same function as described above can also be employed.
Third Embodiment
Optical paths L5 and L6 may be set in a direction to tilt with
respect to a widthwise direction Y.
<Tilt of Optical Path>
An advantage obtained when the optical paths L5 and L6 are tilted
will be described with reference to FIGS. 18A to 18C. FIG. 18A is
an explanatory view schematically showing the arrangement of
light-emitting units 15a and 16a and light-receiving units 15b and
16b.
In this embodiment, the light-emitting unit 15a and the
light-receiving portion 15b are arranged at positions shifted in a
conveyance direction X and face each other in a direction tilting
with respect to the widthwise direction Y. Hence, the optical path
L5 tilts in the conveyance direction X by an angle .theta.5 with
respect to the widthwise direction Y. Similarly, the light-emitting
unit 16a and the light-receiving portion 16b are arranged at
positions shifted in the conveyance direction X and face each other
in a direction tilting with respect to the widthwise direction Y.
Hence, the optical path L6 tilts in the conveyance direction X by
an angle .theta.6 with respect to the widthwise direction Y.
If an end in the conveyance direction is bound by a plurality of
staples ST along the edge, as shown in FIG. 6A or 6C, the end of
the bundle of documents floats in a wavy pattern almost evenly in
the widthwise direction, as shown in FIG. 7A or 8A, and the planar
direction of a floating document D becomes almost parallel to the
widthwise direction Y. In a case in which the optical paths L5 and
L6 are set to be almost parallel to the widthwise direction Y, if
the document D is thin, the document D may be unable to
sufficiently interfere with light on the optical paths. It may be
impossible to detect the floating of the document D, and the bundle
of documents bound by the staples ST may be passed. On the other
hand, if the optical paths L5 and L6 are tilted with respect to the
widthwise direction Y, the detection ranges of detection units SR5
and SR6 widen, and the floating document D can sufficiently
interfere with the light on the optical paths. As a result, the
accuracy of detecting the deformation of the document can be
improved independently of the thickness of the document.
FIG. 18B schematically shows a case in which the optical path L6 is
parallel to the widthwise direction Y, and FIG. 18C schematically
shows a case in which the optical path L6 tilts with respect to the
widthwise direction Y. As shown in FIG. 18B, if the optical path L6
is parallel to the widthwise direction Y, and optical path L6 and
the planar direction of the document D that floats due to the
binding become almost parallel. Even if the document D shields the
light on the optical path, the detection unit may be unable to
detect this, and the stapled document D may be passed. If the
optical path L6 is tilted as shown in FIG. 18C, the planar
direction of the document D crosses the optical path L6, and the
light on the optical path is shielded more easily by the document
D. The accuracy of detecting the deformation of the document D can
thus be improved regardless of the thickness, and the conveyance of
the bound document can be stopped.
The optical path L6 has been described with reference to FIGS. 18B
and 18C. This also applies to the optical path L5. The angles
.theta.5 and .theta.6 may be different or the same. If the angles
.theta.5 and .theta.6 are too small, the improvement of the
detection accuracy is small. If the angles are too large, a
disadvantage for the sensor layout may occur. Hence, the angles
.theta.5 and .theta.6 can be angles within the range of, for
example, 1.degree. (inclusive) to 45.degree. (inclusive). At this
time, lenses (not shown) configured to tilt the optical paths L5
and L6 or components used to support or arrange the light-emitting
units 15a and 16a and the light-receiving units 15b and 16b to tilt
the optical paths L5 and L6 are defined as optical path forming
units.
In this embodiment, the direction to tilt the optical paths L5 and
L6 with respect to the widthwise direction Y is the conveyance
direction X. However, it may be the vertical direction. The optical
paths may tilt in both the conveyance direction X and the vertical
direction. In this embodiment, both the optical paths L5 and L6 are
tilted. However, only one of them may be tilted.
Although tilting the optical paths L5 and L6 promotes to detect the
floating of the document D by the detection sensors SR5 and SR6, a
folded document may be erroneously detected as a bundle of bound
documents. However, a bundle of bound documents can be precisely
detected by discriminating between a bundle of documents and a
folded document based on the detection time or the detection count
of the detection sensor SR6 as the first embodiment. Further, since
such an erroneous detection can be prevented, the flow reading mode
can be conducted without stopping conveying a folded document. It
is therefore possible to prevent conveyance of a folded document
capable of normally being read from stopping and prevent the user
from being promoted to set the document again.
Other Embodiments
Embodiment(s) of the present invention can also be realized by a
computer of a system or apparatus that reads out and executes
computer executable instructions (e.g., one or more programs)
recorded on a storage medium (which may also be referred to more
fully as a `non-transitory computer-readable storage medium`) to
perform the functions of one or more of the above-described
embodiment(s) and/or that includes one or more circuits (e.g.,
application specific integrated circuit (ASIC)) for performing the
functions of one or more of the above-described embodiment(s), and
by a method performed by the computer of the system or apparatus
by, for example, reading out and executing the computer executable
instructions from the storage medium to perform the functions of
one or more of the above-described embodiment(s) and/or controlling
the one or more circuits to perform the functions of one or more of
the above-described embodiment(s). The computer may comprise one or
more processors (e.g., central processing unit (CPU), micro
processing unit (MPU)) and may include a network of separate
computers or separate processors to read out and execute the
computer executable instructions. The computer executable
instructions may be provided to the computer, for example, from a
network or the storage medium. The storage medium may include, for
example, one or more of a hard disk, a random-access memory (RAM),
a read only memory (ROM), a storage of distributed computing
systems, an optical disk (such as a compact disc (CD), digital
versatile disc (DVD), or Blu-ray Disc (BD).TM.), a flash memory
device, a memory card, and the like.
While the present invention has been described with reference to
exemplary embodiments, it is to be understood that the invention is
not limited to the disclosed exemplary embodiments. The scope of
the following claims is to be accorded the broadest interpretation
so as to encompass all such modifications and equivalent structures
and functions.
This application claims the benefit of Japanese Patent Applications
No. 2016-114680, filed Jun. 8, 2016, No. 2016-114683, filed Jun. 8,
2016, and No. 2016-114684, filed Jun. 8, 2016, which are hereby
incorporated by reference herein in their entirety.
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